There is no question that we all make mistakes and I have made plenty my self.
As far as adding cleaner in the tank or ells where for that matter.
I am very skeptical.
The tank and the rest of the system are coated protected, if you add cleaners in the tank then some of the coating will travel down stream and I have no idea what the result is going to be.
What about the gas filter, may be you can dissolve it.
May be it will damage the converters.
I don't know if that makes sense to you.
The method I would prefer is to remove the injectors, and clean them on the bench.
With special equipment.
And last but not list.
You must see the spray pattern and volume, and no cleaner can do that.
Hmm.
Think of it this way.
You have the cleanest windshield in town.
Regards.
aam.